Blog entry by Myrna de Hoop – PhD studentLand is essential to support life, ecosystems and food production. Due to population growth and environmental problems, land is becoming scarce. Especially in drylands, the deterioration in the quality of land is a problem. Dryland systems cover about 40% of the earth surface. Desertification in these areas directly affects about 250 million people. Various factors can cause desertification, such as climatic variations and human activities. My research focuses on rangeland management and the impact on dryland ecosystems. How could we anticipate desertification?

In our research project we look at how plants can work together to survive in very stressful environments. Much empirical work already showed that plants can facilitate each other’s survival in grazed or very dry environments. Big shrubs can for example protect young plants against grazers, thereby increasing survival of young plants. Also, big shrubs might provide shade to decrease drought stress for young neighbouring saplings. In my PhD project we look at how facilitation between plants might disappear when both grazing stress and drought stress become very severe. We expect that with increasing stress facilitation firstly becomes more important, but that at very high stress positive interaction will disappear again. Pinpointing the stress level at which facilitation wanes is crucial to better understand future land degradation in arid ecosystems.